How old are homes in Deerfield, and what does that mean for a deck?
19% of homes in Deerfield's covered ZIP code were built in 2000 or later and 24% before 1960; the largest group dates to the 1960s.
Homes in Deerfield have a median construction year of 1974, so a deck original to a typical house would now be about 52 years old — beyond the point where wood framing, fasteners and flashing can be assumed sound.
Many decks from the 1970s and 1980s were built before today's detailed deck provisions appeared in model codes. Common issues on decks of this age include corroded hangers, posts set directly in soil and ledger boards fastened with nails. Replacement is often the better value than repeated repairs.
That makes Deerfield's housing 9 years older than Lake County as a whole, where the median home was built in 1983. Statewide, the median Illinois home was built in 1971. Among the 102 covered Illinois communities with Census data, Deerfield ranks #49 for oldest housing. In this ZIP code, 24% of homes were built before 1960, 36% between 1960 and 1979, 22% between 1980 and 1999, and 19% since 2000 — the single largest group dates to the 1960s.
| Decade built | Homes | Share |
|---|---|---|
| 2020 or later | 207 | 2% |
| 2010s | 1,042 | 10% |
| 2000s | 766 | 7% |
| 1990s | 1,376 | 13% |
| 1980s | 997 | 9% |
| 1970s | 1,821 | 17% |
| 1960s | 2,011 | 19% |
| 1950s | 1,879 | 17% |
| 1940s | 362 | 3% |
| before 1940 | 320 | 3% |
What does Deerfield's climate mean for deck construction?
Deerfield averages about 122 days a year at or below freezing, 33.6 inches of snow and 32.3 inches of precipitation, based on NOAA 1991–2020 normals.
The nearest NOAA climate station with 1991–2020 normals is Chicago Palwaukee AP, about 4 miles away. It records an average of 122 days a year with a low at or below 32°F — a substantial freezing season. On roughly 79 of those days the temperature climbs back above freezing, so water in wood, soil and gaps between boards repeatedly freezes and thaws.
For Deerfield, that means footings must bear below the locally required frost depth to avoid heaving, and wood surfaces should be kept sealed so absorbed water doesn't split boards over winter. Synthetic decking tolerates freeze-thaw well but still needs the manufacturer's expansion gaps.
Average snowfall near Deerfield is about 33.6 inches a year (Chicago Botanic Garden). That's enough that shoveling and ice-melt choices affect deck surfaces, and stair treads benefit from good texture and drainage.
Precipitation averages about 32.3 inches a year, falling on about 63 days with 0.1 inch or more — wet enough that drainage and flashing still matter, but dry spells also let wood surfaces dry out and check in the sun.
Average summer highs reach about 82°F, and around 17 days a year top 90°F. On a deck with full afternoon sun, dark composite can get uncomfortable on those days, so test samples in the sun before choosing a color.
Which decking material makes the most sense in Deerfield?
For most Deerfield homes, capped composite is the strongest starting point because about 79 freeze-thaw days a year are hard on unsealed wood and roughly 33.6 inches of snow a year means regular shoveling.
Budget, upkeep tolerance and sun exposure on your particular lot still decide the final choice between these options.
| Material | How it handles Deerfield's conditions |
|---|---|
| Pressure-treated pine | Economical; needs sealing to resist freeze-thaw splitting |
| Cedar | Attractive and stable; refinish to keep its color |
| Capped composite | Low maintenance; handles moisture and freeze-thaw well |
| PVC | Lightest and most moisture-proof; premium price |
What kinds of homes are in Deerfield, and how does that shape deck design?
Deerfield has about 10,781 housing units across its covered ZIP code. 72% are single-family detached homes, 12% are attached homes such as townhouses and rowhouses, and about 17% are in buildings with two or more units. Roughly 85% of occupied homes are owner-occupied.
The mix of detached homes and attached or multi-unit housing in Deerfield means deck projects range from large backyard decks to compact rear decks on narrow lots. Lot size, neighbors' sightlines and any association rules shape the right design.
What deck projects are most common in Deerfield?
Based on the age of Deerfield's housing, the largest group of projects is likely to be retrofitting or rebuilding decks added to older homes.
- Retrofit decks on older homes: about 4,572 homes (42%) predate 1970. Here the priority is confirming that add-on decks are properly attached — or rebuilding them freestanding — before any cosmetic work.
- Replacement and major repair: about 4,194 homes (39%) were built between 1970 and 1999, the age group whose original or early add-on decks are most likely to have worn-out framing, connectors and boards.
- Upgrades and expansions: about 1,249 homes (12%) were built since 2010. Their decks are usually sound but small or builder-grade, so enlarging the deck, adding stairs and switching to composite or upgraded railings are common.
When is the best time to plan a deck project in Deerfield?
Deerfield has a defined building season. Spring and early fall offer the most comfortable working weather; winter is a good time to settle the design and apply for permits. Stains and sealers generally need dry weather and moderate temperatures, so plan wood finishing for late spring or early fall.
Do you need a permit to build a deck in Deerfield?
Often, yes — especially for attached or elevated decks — but the rules are set locally. Check with the building department that serves your address: the municipality, or Lake County for unincorporated areas.
For Deerfield, IL, ask the permit office whether your deck needs a permit based on its size, height and attachment to the house, which drawings and inspections are required. Statewide code background for Illinois is on our state page; local rules change, so the building department remains the authority.
How does Deerfield compare with nearby covered areas?
The closest covered area is Lincolnshire, about 2.8 miles from the center of Deerfield's covered ZIPs. Its median home was built in 1991, 17 years later than in Deerfield. Deerfield has 16 percentage points more detached single-family homes (72% vs. 56%), which changes how many projects are backyard decks versus compact townhouse decks. Owner-occupancy is 85% in Deerfield compared with 80% in Lincolnshire. Deerfield's covered ZIP code span about 13.6 square miles of land with roughly 10,781 homes — about 793 per square mile, a low density that usually allows larger decks and freestanding designs.
| Area | Distance | Median year built | Covered ZIPs |
|---|---|---|---|
| Lincolnshire | 2.8 mi | 1991 | 1 |
| Northbrook | 3.7 mi | 1976 | 1 |
| Wheeling | 3.7 mi | 1980 | 1 |
| Highland Park | 3.8 mi | 1963 | 1 |
| Highwood | 4.1 mi | 1969 | 1 |
| Buffalo Grove | 4.4 mi | 1982 | 1 |
Deck planning checklist for Deerfield homeowners
- Confirm your ZIP code is 60015, the covered Deerfield ZIP.
- Find out when your current deck was built and whether it uses pre-2004 treated lumber.
- Ask what footing depth your building department requires for frost.
- Plan stair location and snow storage so winter shoveling doesn't damage boards or railings.
- Probe the ledger, post bases and joist tops for soft wood before planning a resurface.
- Call 811 before any digging so utility lines are marked.

